4. Function overview
Festo P.BE-CMMP-AS-3A-HW-EN 0708NH
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If no setpoint source is activated, then the setpoint is zero.
A ramp generator with an upstream adder is available in the setpoint management. Appro-
priate selectors can be used to select any of the named setpoint sources and use them via
the ramp generator. Two further selectors allow the selection of additional setpoint sources
that are not used via the ramp generator. The final setpoint results from the summation
of all values. The ramp acceleration and braking times can be separately parameterised
depending on the direction.
4.2.4
Controlled torque mode
In controlled torque mode, a particular setpoint torque, which the servo controller is to
generate in the motor, is specified. In this case, only the current regulator is activated
since the torque is proportional to the motor current.
4.2.5
Controlled speed mode
This operating mode is used when the motor speed is to be kept constant, regardless of
the effective load. The motor speed is exactly the speed specified in the setpoint manage-
ment.
The speed regulation circuit cycle time of the CMMP-AS servo positioning controller is
250 µs.
The speed controller is designed as a PI controller with an internal resolution of 12 bits per
revolution/min. To suppress "wind-up effects", the integrator function is stopped when
subordinate limits are reached.
In the controlled speed mode, the current regulator and the speed regulator are active.
Analogue setpoint inputs can optionally be used to define a "reliable zero". If the ana-
logue setpoint lies within this range, then the setpoint is set to zero ("dead zone"). This
can be used to suppress malfunctions or offset drift. The dead zone can be activated/de-
activated and the width can be adjusted.
The actual values of speed and position are determined from the internal motor encoder
system, which is also used for commutation. An encoder interface can be selected for pro-
viding the actual values used for speed regulation (e.g. reference encoder or an appropri-
ate system at the external incremental encoder input). The actual speed value for speed
regulation is then obtained from (e.g.) the external incremental encoder input.
The speed setpoints can be internally specified or also derived from the data of an external
encoder system (speed synchronisation via [X10] for the speed regulator).
Summary of Contents for CMMP-AS-C2-3A
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